Curl Secret in Cells

The study led by Duane Harland and his team investigated the cause of natural hair curliness by examining fine curly merino sheep wool, as human hair was too coarse for detailed analysis. They found that the curl in hair is due to the arrangement of two different cell types: shorter paracortical cells lining the inside of the curve and longer orthocortical cells on the outside. This discovery contradicted the theory that more cell division on one side caused the curl. The findings suggested that cell type and length are crucial in determining hair curliness, which could influence the development of new hair care products in the $85 billion global market.